I had a manager who would write the most hideous, impossible-to-debug code imaginable and always have some sort of microbenchmark as some kind of justification. At the time I was young enough in my career to just think he was wiser than I was, but upon reflection (and remembering some of the stuff he did involving FFI-ing C into Haskell all the time), I realized that he just didn't he didn't like people criticizing his code, though the first hint should have been when he refused to answer my questions about actual performance profiling of our codebase.